HT7703 Touch Dimmer Features * * * * * Wide operating voltage: 8V~12V Provided brightness control of incandescent lamps without using mechanical switches Reducing the power dissipation Operating on 60/50 Hz line frequency Touch sensitive sensor input General Description The HT7703 is a monolithic CMOS circuit designed for brightness control of incandescent lamps. The output of the HT7703 triggers a triac connected in series with the lamp. There are four specified levels of brightness through which the output can be stepped. The stepping function may be selected to operate in one of two different modes by a MODE selector. Pin Assignment Block Diagram 1 26th Mar '97 HT7703 Pin Description Pin No. Pin Name Description 1 ZC Zero crossing input 2 OSC1 Oscillator 1 3 OSC2 Oscillator 2 4 SENSE Touch sense input 5 T1 Touch signal detector 1 6 T2 Touch signal detector 2 7 VDD Positive power supply 8 60/50 60/50 Hz selection 9 MODE Mode selection 10 NC No connection 11 OUT Trigger output 12 NC No connection 13 VSS Negative power supply 14 PWR Power on reset Electrical Characteristics Symbol Parameter Test Condition VDD Condition -- Min. Typ. Max. Unit 8 10 12 V -- 0.5 1 mA VDD Operation Voltage -- IDD Operation Current 10V VIL "Low" Input Voltage 10V -- -- -- 2 V VIH "High" Input Voltage 10V -- 8 -- -- V RPU1 Pull-Up Resistance (60/50, MODE) 10V VI=0V 400 600 800 K RPU2 Pull-Up Resistance (PWR) 10V VI=0V 1 1.5 2 M IOL Sink Current (OUT) 10V VOUT=1V 25 80 -- mA IOH Source Current (OUT) 10V VOUT=9V -20 -60 -- A FCLK Clock Frequency 10V Rosc=68K -- 180K -- Hz 2 No load 26th Mar '97 HT7703 Function Description The operating mode of the circuit is selected by a MODE input as follows: After power on, the initial state stays off. Following that, whenever the sensor plate is touched, the output jumps to the next level of brightness. Application Circuit 3 26th Mar '97